On 1 August 2014 03:42, Aaron Lu <aaron.lu@xxxxxxxxx> wrote: > A workaround from user space is to specify the backlight interface you > want to use in xorg.conf, an example is here: > https://bugs.debian.org/cgi-bin/bugreport.cgi?msg=78;att=0;bug=651741 > > Section "Device" > Identifier "Intel Graphics" > Driver "intel" > Option "AccelMethod" "sna" > Option "Backlight" "intel_backlight" > Driver "intel" > BusID "PCI:0:2:0" > EndSection Thank you. This works both in v3.16-rc and in the current Ubuntu 14.04 latest update. Now user-interface brightness controls work before AND after a suspend. The only difference in the user experience is that now minimum brightness on the brightness sliders gives a completely dark screen rather than just a very dimly lit screen. I can live with this. I'm guessing this should be regarded as a work-round rather than a final solution that might eventually form part of the kernel. Should I report it as such back in the downstream Ubuntu/Launchpad bug? If in future, when this is addressed in the kernel, further testing is required please let me know. I'd be happy to assist. Thank you for your help, John Marsden -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html